1. SUBMITTED COPY IS AVAILABLE ON ODFW PUBLIC WEBSITE: HTTP://WWW.DFW.STATE.OR.US/WILDLIFE/RESEARCH/INDEX.ASP. HTTP://WWW.DFW.STATE.OR.US/WILDLIFE/RESEARCH/INDEX.ASP IDENTIFYING MULE DEER MIGRATION CORRIDORS THREATENED BY HIGHWAY DEVELOPMENT Coe et al. 2015, Wildlife Society Bulletin, in press

2. POPULATION TRENDS

3. MIGRATION CORRIDOR ANALYSIS

4. MIGRATION USE

5. HIGHWAY SURVEYS 2005-2010 deer-vehicle collisions monitored on near-daily basis by ODFW and ODOT in an attempt to collect every deer carcass during that period. This data represented a minimum number of actual DVCs because some mortally wounded deer move off highway. 1,901 DVCs were recorded, of which 1,269 (67%) were during spring or fall migration periods.

6. ODOT DISPATCH COLLISION DATA

7. CORRELATION OF RISK OF DVC AND MIGRATION PROBABILITY Highway 97: r = 0.93 Highway 31: r = 0.85

8. LANDSCAPE COVARIATES Tree canopy cover Distance from water Distance from development Topographic curvature Annual average daily traffic (AADT)

9. COUNTED DVC BY 500-M SEGMENT

10. CALCULATED MEANS WITHIN BUFFERED SEGMENTS

11. MODEL RESULTS FOR DVCS ~ LANDSCAPE COVARIATES

12. MODEL COEFFICIENTS FOR TOP- RANKED MODEL Covariate a Highway 97 Highway 31 Standardized coeff. Canopy Cover 0.050 −0.234 Topography −0.154 0.025 Distance to Development −0.135 0.175 Migration Use 0.340 0.369 Distance to Water −0.102 −0.013 Traffic 0.152 1.668 Traffic 2 −0.177 −1.557

13. BARRIER EFFECT

15. CONCLUSIONS Mule deer migration corridors were the strongest predictor of deer-vehicle collisions on both highways Highway re-construction should be preceded by studies that identify migration pathways or DVCs documented. Roadside landscape features helped in models but were inconsistent between highways. Migration corridors are driven by larger landscape features. Managers attempting to maintain migratory corridors on existing highways should focus mitigation measures where DVCs are highest and, secondarily, where AADT is highest Migration corridor layer represents entire population of mule deer in this area so is useful for other wildlife management planning.